Hydrocarbons, such as oil and gas, are commonly obtained from subterranean formations that may be located onshore or offshore. The development of subterranean operations and the processes involved in removing hydrocarbons from a subterranean formation typically involve a number of different steps such as, for example, drilling a wellbore at a desired well site, treating the wellbore to optimize production of hydrocarbons, and performing the necessary steps to produce and process the hydrocarbons from the subterranean formation.
When drilling a wellbore to the desired depth, a drill bit cuts into the subterranean formation, releasing cuttings of the formation into the wellbore. After drilling the wellbore to a desired depth, the cuttings left in the wellbore typically settle at the bottom of the wellbore. In vertically oriented wellbores, these cuttings fall to the bottom of the hole. However, in horizontally oriented or deviated wellbores, a portion of the cuttings cannot be removed and thus the cuttings can accumulate along the low side of the wellbore over long distances.
After drilling a wellbore that intersects a subterranean hydrocarbon-bearing formation, it is common practice to set a string of pipe, known as casing, in the well to isolate the various formations penetrated by the well from the wellbore. The casing may be run into the wellbore and cemented in place. In conventional cementing operations, a cement composition is displaced down the inner diameter of the casing until it exits the bottom of the casing into the annular space between the outer diameter of the casing and the wellbore. It is then pumped up the annulus until a desired portion of the annulus is filled.
Certain casing string systems allow for auto-fill while running the casing into the wellbore. Auto-fill enables mud from the wellbore to flow into the casing string through the “shoe” at the bottom of the casing string and up through the casing as the casing is lowered into the wellbore. As the casing string is run to depth in deviated wells, cuttings and debris along the low side of the wellbore can enter the casing shoe track. If the casing string is equipped with an auto-filling float collar, these cuttings can be swept into the main casing string. Unfortunately, accumulation of debris above the float collar can negatively affect cementing operations by preventing a plug from sealing properly on the float collar. Cuttings can also become lodged in the float valve and cause clogging and loss of auto-fill. This clogging may prevent the casing string from auto-filling, causing the casing string to act as a plunger forcing mud into the formation, which could prematurely fracture the formation. This clogging could also cause the float valves to not function properly, which could disable the primary function of the equipment. Some existing casing string systems include filters to prevent this debris from reaching the main casing string while running the casing. However, existing systems with the filters can become clogged and cannot be flushed out once clogged.